Deformation Behavior of Mg-alloy-based Composites at Different Temperatures Studied by Neutron Diffraction

Abstract

Deformation mechanisms in a Mg-Al-Ca alloy reinforced with short alumina fibres were studied by acoustic emission and neutron diffraction method (ND). The microstructure after deformation was observed by electron microscope (SEM). The fibres plane orientation with respect to the loading axis was found to be a key parameter, which influences the active deformation processes, such as twinning and dislocation slip. In-situ neutron diffraction tests were performed at room temperature (RT) and 100 • C. The relative twin volume in the matrix as a function of the applied compressive load were evaluated from the ND tests. Acoustic emission results indicate a larger twinning activity and more frequent fibre cracking in sample with perpendicular fibre plane orientation. Both of these mechanisms increase in magnitude at 100 • C.